Field
The present specification generally relates to electromagnetic transducers and, more particularly, electromagnetic transducers having a self-centering characteristic in an axial direction.
Technical Background
Electromagnetic transducers may include linear motors and linear generators, for example. A linear motor converts alternating current applied to a coil into linear translation of a magnet or coil, while a linear generator converts linear translation of a magnet into alternating current in a coil. Conventional linear electromagnetic transducers of these types incorporate return springs to prevent the magnet from escaping the gap in which it is disposed, as well as to define the neutral position for the reciprocating oscillation movement of the magnet or coil. However, use of springs in the electromagnetic transducer is costly, and may lead to a large and heavy device. Further, such return springs cause lateral forces on the bearing of the transducer, which may limit the lifetime of the device. Additionally, it may be difficult and unpractical to change the spring rate of an installed return spring, especially during operation. As such, electromagnetic transducers incorporating return springs have a static spring rate.
Accordingly, a need exists for alternative linear electromagnetic transducers that have a self-centering magnet without the need for return springs.